Scientific research show that indoor air quality is often worse than the quality of the outside air. This also applies to large cities with polluted outdoor air. Since people spend 90% of their time indoors, air pollution in buildings can pose a serious risk to health.

Fortunately, the quality of the indoor air can be largely controlled. In this article, we will show you a number of important polluters of indoor air and what you can do to improve the air quality in your house.

Biological vs chemical polluters.

Biological polluters

Biological polluters include viruses, bacteria, fungi, animal or human dander, dust mites and pollen from plants.

Various viruses, such as the flu, measles, and chickenpox viruses, spread through the air. Although vaccines are available, you run a higher risk of developing these diseases in (busy) indoor spaces. This is especially true for flu. Regular ventilation of these rooms reduces this risk.

Dust mites are a tiny animal that can be found worldwide. The feces of these animals can move through the air while vacuuming or brushing your home. The dust mites thrive best at temperatures between 20 and 30 degrees Celsius and humidity of 60 to 80%. Most often they live in mattresses or carpeting. The following measures make it difficult for the dust mites to survive:

  • Use synthetic padding for pillows instead of feathers
  • Use a mattress protector with anti-allergy function
  • Change your beddings weekly
  • Use nylon or cotton blankets instead of wool
  • Wash your bedding at high temperature (50 degrees Celsius)
  • Reduce the habitat of the dust mites by removing carpets, rugs, and curtains where possible
  • Use tightly tensioned sheets to reduce the accumulation of dander

Pets can also affect air quality due to dander, feces, hair, and saliva. Not keeping pets is the most effective measure against this form of air pollution. If there are pets in the house, keep them away from the bedroom and make sure they do not come into contact with carpets and upholstered furniture.

We are exposed to different types of fungi on a daily basis, both indoors and outdoors. Fungi can live indoors on various materials, such as wood, insulation material, wallpaper, and plaster. Some fungi can cause health problems. Respiratory problems are the most common. Fungi grow in damp places. Leaks, problems with water drainage and high humidity are therefore risk factors for mold growth in your home. In addition, poor ventilation and temperature fluctuations indoors also play a role in the development of mold.

Pollen from plants spreads through the air and can cause varying complaints: sneezing, coughing, watery eyes, shortness of breath, dizziness, fever, and gastrointestinal problems. The amount of pollen produced varies per plant species. Remember to check the pollen production of your indoor plants.

Chemical polluters

Carbone monoxide

Carbon monoxide is a colorless and odorless substance that arises from incomplete combustion of carbon. Inhaling this gas can lead to various complaints, such as headache, dizziness, vomiting and overall weakness. At high levels of carbon monoxide in the air, you can even die. Gas cooking, barbecuing and gas heaters are sources of carbon monoxide production in and around the house. It is very important to ventilate during cooking. Since you cannot smell or see the substance, a carbon monoxide meter is a useful tool to monitor the amount of carbon monoxide. It’s a good idea to install this meter in your bedroom. This way you will be warned about carbon monoxide in the air during your sleep. Maintenance of your cooking and heating equipment is also important.

Tobacco smoke

Tobacco smoke is an important indoor chemical polluter. Inhaling this smoke can cause numerous health problems. Infections, respiratory problems, and various types of cancer are associated with inhaling tobacco smoke. Quitting smoking is the only real solution to the problem of tobacco smoke in the home. Good ventilation and smoking at an open window are not particularly effective.

Volatile organic compound

Many household materials, such as cleaning products, paints, building materials and cosmetics contain volatile organic compounds (VOC). These are substances that evaporate at room temperature and thus end up in the air. The air quality is affected by these volatile organic compounds and they can be harmful to health. Formaldehyde is a well-known example. This substance is found in paint, cosmetics, and the glue of insulation material.

Measures to reduce the content of VOC in your home:

  • Use household products in accordance with the regulations.
  • Ventilate when using household products.
  • Make sure household products are properly sealed.


Radon is a waste product of uranium and occurs in the soil. Radon enters the house through openings in the foundation of a house and air pressure differences between the soil and the house. High concentrations of radon in the home are related to lung cancer. In particular, the combination with smoking increases the risk of this type of cancer.


Pesticides are often used as a mean of combating fungi, insects, or other unwanted inhabitants of your home. However, these pesticides affect air quality. The health risks associated with the use of pesticides vary by product. Irritation of the eyes, nose and throat are common. Serious problems, such as kidney and nerve disorders, can be the result of (long-term) pesticide use.


Asbestos is a toxic substance that in the past was widely used for products in and around the house. Asbestos is found in boilers, roofing and insulation material of house built before the 1970s. As long as the asbestos is not disturbed, there is little danger to the residents. The danger to health arises as soon as the asbestos fibers come loose and are inhaled. In many cases, asbestos does not need to be removed. Removal of asbestos is complicated and must be done by a specialist.

Effects of indoor air pollution

The effects of indoor air pollution are variable. Common complaints include irritation of the skin, eyes and throat, mucus formation, headache, dizziness, nausea, breathing problems and fatigue. Long-term exposure to air pollution or exposure to hazardous substances may result in more serious consequences. For example, the risk of lung cancer is increased by inhaling asbestos fibers and tobacco smoke. Carbon monoxide poisoning can even lead to sudden death. Some people are particularly sensitive to air pollution. These are usually people with underlying health problems. For example, in asthma patients, an attack can be triggered by inhaling harmful substances. This can be acutely life-threatening.

Measures against indoor air pollution

The possible sources of indoor air pollution are numerous and diverse. From insulation material to cooking equipment and from plants to cleaning products. Some air polluters, such as dust mites and mold, require a specific approach. Nonetheless, there are general measures that you can take to ensure indoor air quality:

Checking polluting sources

  • Keep a close eye on potential indoor polluters indoors
  • Check your home for defects (e.g., water leaks or the presence of asbestos in your home)
  • Use chemical household products moderately and ensure safe storage
  • Reduce the emissions of gas stoves
  • Prevent excessive humidity in your home by, for example, drying the laundry outside, using an extractor hood when cooking and keeping your house at the recommended temperature


Letting outdoor air into your home is a good way to drive out air indoor polluters. Opening windows and doors, preferably against each other, ensures a good flow of air. Daily ventilation is wise. Ventilation is particularly important for activities that cause a lot of pollution or moisture, such as cooking, dyeing, cleaning, or showering.

Talk to the doctor

It is not always easy to determine whether your ailments are related to your living environment. You should see your doctor in case of unexplained illness. If necessary, he or she will call in a specialist to examine your home for factors that are harmful to health.

Betsy Wilson

Betsy is a true science nerd, down to the glasses. Her words, not mine! She works as a nurse specializing in pediatric nursing. She holds a Master's degree from the University of Pennsylvania. She is passionate about all thing pregnancy and baby-related.